Posting just to gather some voice, and hopefully there's more supporting evidence from other people on this issue.
I have (almost) exactly the same issue.
- AirPod Pro 2
- Using "S" size ear tip (both sides)
- Left bud not charging, right bud working just fine
- First-hand AirPods Pro 2
- All parts are genuine (including ear tips)
Edit: also, already tried cleaning the case with q-tips and the dust blower that people used to clean camera lenses, they did not solve the issue.
90% of the time it will not charge when I put it in the case on first try. I could either take it out and put it back in again and keep on repeating until it charges, or, push the left bud towards the center of the case horizontally (not downwards into the slot). Then the charging indicator will light up, but more than 50% of the time when I do this, as soon as I release my fingers, it will stop charging again… which made me suspect it was the ear tip causing the problem.
Since mine is still under warranty, I sent them back for inspection/repair.
1st time: I thought only the left bud had problems, but the technician said both sides had charging problems, so both sides were replaced.
2nd time: 2 months later the same problem occurred, from rarely not charging to often. The frequency increases as if something is degrading, but if it's the ear tips causing the problem, then this doesn't explain anything because they have never been replaced before (procedure: ear tips to be removed before handing in for inspection). This time the technician said there was nothing wrong with them.
At the time of writing, it's been another 2 months since the second inspection. Probably gonna send it back for the third time but mentioning that the ear tips are highly suspected to be preventing the charging connectors from contacting properly.